The present invention generally relates to catheter systems. More specifically, certain embodiments of the present invention related to four-way steerable catheter systems.
Current catheter systems with movable guide wires present disadvantages such as limited steerability, which is currently dependent upon the torque control of the movable wire. Steerability is highly significant in a cardiovascular procedure, such as percutaneous transluminal coronary angioplasty (PTCA), or angioplasty, because less steerability results in greater time spent in the body and more possible patient trauma. Multiple insertions of guide wires and catheters can lead to thrombosis because, for example, coagulation may commence along a guide wire surface and be forced into the heart when a catheter is slid over the guide wire. Furthermore, there are some blockages which cannot be reached with presently known equipment.
As procedures become more and more complex, physicians have a need to pinpoint exact physical locations inside the body particularly the heart. The currently available catheters are 2-way deflectable, meaning the doctor finds an area fairly close to what he wants to view and then torques the catheter to try to maintain the correct field of view. Currently physicians have resorted to using sterile tape to try to hold the handle and the shaft in an exact location. This can be quite problematic when the patient moves his or her legs, as the entire ultrasound system then gets moved away from the area of interest. In some teaching hospitals, a resident must stand at the patient's bedside holding the catheter to assure good visualization through the procedure. This exposes the resident to radiation that he/she would not normally be required to absorb. Traditionally 1 or 2 pull wires are placed in a catheter allowing the intracardiac echocardiography (ICE) or intravascular ultrasound (IVUS) catheter to bend either one direction or 2 directions. An example of one able to move both ways is shown in FIG. 1.
Thus, there is a need for catheter systems and methods for improved positioning of a catheter. There is also a need for systems and methods providing improved control of a catheter.